Converter discharging

[cosninocanines]

When dry camping I notice a hum from the converter and lose my battery charge overnight. 2 questions here. Should the converter make any noise when I'm not hooked to any outside source of electricity? Does the converter need to be plugged in or connected to the 12 volt system while I'm dry camping?
Thanks for any help on this, I plan on replacing the old Todd converter in my 2000 Mallard 5th wheel no matter what the problem is so any advice on that would also be appreciated.

 

[Gary RV_Wizard]

I can't imagine why a converter would hum when not connected to shore power or genset - the hum is from the 12V output stage. Nor can I conceive of any way for a reverse 12V feed to make it hum. Very strange!  ???

Losing the charge overnight is likely a different issue - a combination of loads on the battery and mabe a weak battery as well.  There are usually many tiny loads on the 12V system - fridge circuit board, water heater circuit borad, detectors, etc. as well as any lights you may have used an dthese can easily run down a weak battery.

 

[Lou Schneider]

Could the hum be the sound of the cooling fan turning on?  This could happen if something else inside the converter has gone bad and is generating heat when it's connected to the battery (the fan being 12 volts and powered by the battery backfeeding into the converter).

Charge the battery, then disconnect the converter and see if the battery still goes dead overnight.  You'll have to remove one of the 12 volt output wires to isolate the converter.  Be sure to tape the bare end so it doesn's short against anything.  If the battery doesn't go dead you have located the problem.

Many Todd converters have failed and they are out of business.  I'd suggest something like the Intellipower and it's associated ChargeWizard.

 

[John From Detroit]

Gee, I thought the HUMM was from the 120vac INPUT state, or more specifically loose lamanations on the transformer

If the only power in the rig is DC nothing should humm.. NOTHING, though fans may wirr

Perhaps it's in inverter, they can humm

In any case... I'd have someone look at it... (Or in my case I'd look into it, since somewhere I have a piece of paper that says I know how to do that kind of stuff)

 

[woodartist]

Well, is the hum "about" the same frequency of a Flourescent light?

 

[cosninocanines]

Thanks for the help, my wife has informed me (a retired heavy equipment operator) that the sound is really a high pitched whistle not a hum. Oh well, if I hear it it is loud. Talked with our local RV center today and they say it can't happen, to which I reply that when I disconnect the converter it stops. No inverter here as I only use the 12 volt stereo over and above the usuall lights etc.

 

[John From Detroit]

If a converter is making a high pitched noise when it's only hooked to 12vdc something is WRONG.

However an INVERTER... That's another story, it can make sounds, though it should not

I can think of a few things but w/o the schemetic diagram I can not be specific

 

[Jeff]

Thanks for the help, my wife has informed me (a retired heavy equipment operator) that the sound is really a high pitched whistle not a hum. Oh well, if I hear it it is loud. Talked with our local RV center today and they say it can't happen, to which I reply that when I disconnect the converter it stops. No inverter here as I only use the 12 volt stereo over and above the usuall lights etc.

The fact that you use only 12v appliances does not necessarily rule out an inverter running in the background.

 

[cosninocanines]

That was it, picked up a new 9200 converter with the built in wizard and all is well. Thanks to everybody that helped us on this.